#include<stdio.h>
int main()
{
	int a,b,c;
	scanf("%d%d%d",&a,&b,&c);
	if(a+b<=c||a+c<=b||b+c<=a)
	printf("not a triangle\n");
	else
	{if(a*a+b*b==c*c||a*a+c*c==b*b||b*b+c*c==a*a)
	printf("yes\n");
	else
	printf("no\n");
	}
	return 0;
 } 
